Radio communication systems have been widely used today, including cellular phone systems and wireless local area networks (wireless LANs). In such a radio communication system, various control signals or control parameters in addition to user data may be transmitted and received between communication apparatuses. The control signals or control parameters permit the communication apparatus to control radio communication.
For example, there is performed a process in which a mobile station transmits a ranging code to a base station, and the base station controls transmission power and transmission timing of the mobile station based on a received result of the ranging code. Further, there is performed a process in which a mobile station informs the base station of information indicating a measurement result of radio quality, and the base station determines a modulation scheme of user data based on the measurement result. In addition, there is performed a process in which a mobile station transmits information indicating a band request to the base station, and the base station allocates a radio resource to the mobile station according to the band request (e.g., refer to the following two literatures).
(1) The Institute of Electrical and Electronics Engineers (IEEE), “IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems”, IEEE802.16-2004.
(2) The Institute of Electrical and Electronics Engineers (IEEE), “IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems”, IEEE802.16e-2005.
However, when the above-described various control sets are performed individually, a number of control signals or control parameters are transmitted and received between communication apparatuses. Therefore, a number of radio resources are consumed. As a result, radio resources allocatable for transmitting and receiving user data are reduced to thereby cause a decrease in a throughput of radio communication.